Golf club putter head

ABSTRACT

A golf club putter head having putter body with a toe region, a central region, and a heel region, the central region having a front recess and a rear recess separated by a central wall joining the heel and toe regions. Front and rear inserts are disposed within the respective front and rear recesses. This construction affords structural integrity and greater manufacturing ease over the construction of putters having toe and heel regions that are entirely separated from each other. The inserts preferably are formed of materials having a lower density than that of the putter body, with the particular material being selected according to a golfer&#39;s preference in feel. A decorative element can be included with the rear insert, to achieve final head weighting and cosmetic appeal. The thickness of the central wall, and the density and thickness of the inserts, are selected to provide the putter head with a desired moment of inertia.

BACKGROUND OF THE INVENTION

[0001] This invention relates generally to golf club heads and, more particularly, to golf club putter heads providing an enhanced feel and sound.

[0002] The beginning and the end of each hole of a round of golf present different and unique challenges to a golfer. The drive off a tee requires hitting a golf ball over a large distance, with accuracy in its direction. The putting portion of golf requires hitting the same golf ball over a much shorter distance, but with great accuracy while attempting to hit the ball into a small cup or hole.

[0003] Two common characteristics important to a golfer are the “feel” and “sound” when the golf ball is contacted by the golf club. For putting, the “feel” and “sound” of the putter are largely determined by the material located at the putter head's striking face (the portion of the putter that contacts the ball). A unitary body design, in which the putter head is composed of a single material, is most common for putters. Forged carbon steel is a particular favorite for the putter head, of its soft feel and quiet sound.

[0004] It also is common for the putter head to incorporate a front insert, to modify the putter's “feel” and “sound.” The insert normally is composed of a different material, e.g., a polymeric or other non-metallic material. These front inserts usually are rigidly attached to the putter head using an adhesive material or threaded fasteners, although removable, replaceable inserts also have been used. These front inserts normally are placed in a front recess carved into the putter's head's front surface. A variety of front recesses have been proposed, having a variety of shapes and sizes. These include recesses having a uniform depth between the head's heel and toe, as well as recesses having a variable depth, typically with a center location being the deepest.

[0005] Another desirable characteristic of a golf club is its “forgiveness,” which relates to the club head's moment of inertia about a vertical axis extending through the club head's center of gravity. The use of heel- and toe-weighting to provide “forgiveness” is a common practice. U.S. Pat. No. 5,938,543, for example, discloses a putter having metallic heel and toe masses separated by a center segment composed of a lower density elastomer, i.e., a thermoplastic polyurethane. Plastic molding operations suitable for forming the center segment and connecting the metallic heel and toe segments of the club head can include resin transfer molding, injection molding, reaction injection molding, and compression molding. The use of an elastomeric center segment allows for increased heel and toe weighting of the putter head. Accordingly, the heel and toe regions may be designed separately at specific desired weights and the entire club head then assembled.

[0006] Finally, a number of putters have included a shallow recess at the rear of the putter body, behind the striking face. This rear recess can carry an insert bearing a logo engraving or paint. Sometimes, a decorative badge can be adhesively attached to the rear insert.

[0007] However, there has been no attempt heretofore to combine the enhancement of putter performance and appearance by disposing inserts in the front and rear portions of the putter, said inserts being separated by a wall joining the toe and heel portions of the putter. There has also been no attempt to vary the “feel”, “sound” or “forgiveness” of the putter by varying the dimensions and composition of these inserts and the thickness of the wall which is located between these two inserts.

SUMMARY OF THE INVENTION

[0008] The present invention resides in an improved golf club putter head, having both a front insert and a rear insert, configured to allow the putter head to provide an enhanced performance for the golfer, including having a selected feel, sound, and forgiveness. In particular, the putter head includes an elongated body having a toe region, a central region, and a heel region. The central region includes a front recess, a rear recess, and a wall separating the front and rear recesses and joining the elongated body's toe and heel regions. Further, a front insert having an exposed striking surface is located within the front recess body, and a rear insert having an exposed rear surface is located within the rear recess. The wall of the putter body's central region has a minimum thickness that is less than or equal to the maximum thickness of the front insert and that is less than or equal to the maximum thickness of the rear insert. In addition, the combined thickness of the wall and the front and rear inserts is selected to provide enhanced putting performance for a golfer.

[0009] In more detailed features of the invention, the front insert is formed of a metallic material having a density less than that of the elongated body. In addition, the front and rear inserts, together, have a mass that is at least 30 grams less than an equivalent volume of the material that forms the elongated body.

[0010] In other more detailed features of the invention, the toe and heel regions of the elongated body comprise at least 70% of a total mass of the putter head. The thickness of the wall of the elongated body ranges between about 0.1 mm and 3 mm. Further, the thickness of both the front insert and the rear insert ranges between about 0.2 mm and 4 mm, and at least one of the inserts has a thickness that varies along a substantially vertical direction. The rear insert can include a plate and an exposed decorative element.

[0011] Other features and advantages of the present invention should become apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a front elevational view of a first embodiment of a golf club putter head in accordance with the present invention.

[0013]FIG. 2 is a rear elevational view of the golf club putter head of FIG. 1.

[0014]FIG. 3 is a top plan view of the golf club putter head of FIG. 1.

[0015]FIG. 4 is a cross-sectional view of the putter head, taken along lines IV-IV in FIG. 1.

[0016]FIG. 5 is a cross-sectional view similar to that of FIG. 4, but of a second embodiment of a golf club putter head in accordance with the invention.

[0017]FIG. 6A is separate cross-sectional view of the front and rear inserts of the golf club putter head of FIG. 5.

[0018]FIG. 6B is a separate cross-sectional view of the golf club putter head of FIG. 5, with the front and rear inserts removed.

[0019]FIG. 7 is a cross-sectional view similar to that of FIG. 4, but of a third embodiment of a golf club putter head in accordance with the present invention.

[0020]FIG. 8 is a cross-sectional view similar to that of FIG. 4, but of a fourth embodiment of a golf club putter head in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] With reference now to the illustrative drawings, and particularly to FIGS. 1-4, there is shown a golf club putter head 10 in accordance with a first preferred embodiment of the invention. The putter head includes an elongated putter body 12 having a toe region 14, a central region 16, and a heel region 18. The central region includes a front recess 20, a rear recess 22, and a central wall 24 that separates the front and rear recesses and joins together the toe and heel regions. A front insert 26 having an exposed striking surface 28 and a rear surface 30 is located within the front recess, and a rear insert 32 having a front surface 34 and an exposed rear surface 36 is located within the rear recess. A sole 38 extends along the underside of the putter head, from the toe region to the heel region.

[0022] In the preferred embodiment of FIGS. 1-4, the central wall 24 of the central region 16, the front insert 26, and the rear insert 32 all have substantially uniform thicknesses. The thickness of the central wall preferably is selected to be less than or equal to the thicknesses of both the front insert and the rear insert. The presence of the front and rear inserts allows a greater portion of the putter head's mass to be located in the putter head's toe and heel regions 14, 18, thus providing the golfer with enhanced “forgiveness.” In addition, the combined thicknesses of the central wall and the front and rear inserts can be customized to provide the golfer with an enhanced putting performance. Although the depicted putter head 10 has a generally blade-like configuration, it will be appreciated that other configurations (e.g., a mallet configuration) could alternatively be used.

[0023] The location of the rear insert 32 relative to that of the front insert 26 is indicated by broken lines in FIG. 1. As further shown in FIG. 1, a decorative shallow groove 40 encircles the front insert. This groove preferably is filled with paint having a color contrasting with that of the putter body 12. Although the inserts and the front and rear recesses 20, 22 are shown as having generally ovular shapes, it should be understood that other shapes could alternatively be used. Examples of such alternative shapes include parabolic, rectangular, and trapezoidal shapes.

[0024] The length L1 of the front insert 26, measured along an axis extending from the toe region 14 to the heel region 18, preferably is between about 40% and 60% of the putter body's total length L. More preferably, the length L1 is between about 45 and 55% of the length L and, most preferably, is about 50% of the length L. The length L2 of the rear insert 32, likewise measured along an axis extending from the toe region to the heel region, preferably is between about 25% and 50% of the putter head's length L. More preferably, the length L2 is between about 35% and 45% of the length L and, most preferably, is about 40% of the length L.

[0025] The height H1 of the front insert 26 preferably is at least about 70% of a putter body's total height H, and the height H2 of the rear insert 32 preferably is between about 50% of the height H and about the same height as the front insert. The front and rear inserts are located in the respective front and rear recesses 20, 22, in the putter head's center region 16, as best shown in FIG. 4. The depths of the front and rear recesses are selected according to the thickness T of the central wall 24. Preferably, the front and rear recesses are configured to represent between about 10 and 20% of the putter head's total volume. This configuration allows a greater proportion of the putter head's mass to be located in its toe and heel regions 14, 18 and in its sole 38.

[0026] In the embodiment of FIGS. 1-4, the putter head 10 preferably is formed of forged carbon steel or cast stainless steel. The putter head also preferably has a total mass of about 340 grams, before the front and rear recesses 20, 22 have been created. In a preferred embodiment, the combined volume of the two recesses represents the removal of about 50 grams (i.e., about 15%) of the putter head's total mass. The recesses are then filled with the inserts 26, 32.

[0027] The front and rear inserts 26, 32 preferably are formed of an aluminum alloy, having a density of about 2.7 g/cc. This contrasts with the density of the steel material of the putter body 12, which is at least about 7.7 g/cc. In one preferred embodiment, the total mass of the two inserts is about 14 grams, and an additional gram or so of mass is provided by an adhesive layer 42 that secures the inserts in their recesses 20, 22. This yields a reduction in total mass of about 35 grams, which in turn allows a greater proportion of the putter head's total mass to be redistributed to the toe and heel regions 14, 18 and/or to the sole 38. This redistribution provides a greater moment of inertia, to resist twisting of the putter head 10 upon impact with a golf ball (not shown). It will be appreciated that the inserts could be formed of alternative materials, including polymers and composite materials, and that the putter body likewise could be formed of alternative materials, including other metals and alloys. Accordingly, amount of weight redistribution might vary, depending upon the materials used to form the putter body and the inserts.

[0028] Preferably, the toe and heel regions 14, 18 each comprise at least about 35% of the putter head's total mass. The mass of the central region 16, including the central wall 24 and the portion immediately surrounding the recesses 20, 22, preferably comprises between about 20% and 29% of the putter head's total mass. Therefore, in one example, the contributions of the toe region, the central region, the inserts and heel region are 35%, 28%, 2% and 35%, respectively. In an alternative example, the mass distribution is 35%, 21%, 4% and 40%, respectively. The slightly higher mass in the heel region in the second example may be due to a hosel 44. Alternatively, the toe region may be slightly increased in mass to more effectively resist twisting.

[0029] As stated above, the preferred materials for the putter body 12, including the central wall 24, include forged carbon steel and cast stainless steel. In one preferred embodiment, the wall has a thickness of at least about 0.1 mm, and preferably about 1 mm. The wall can have a uniform thickness (FIG. 7), or it can have a gradual taper (FIGS. 4 and 5). As shown in FIGS. 6A and 6B, the wall has a minimum thickness M that is less than or equal to a maximum thickness M1 of the front insert 26 and less than or equal to a maximum thickness M2 of the rear insert 32.

[0030] In a preferred embodiment, the front and rear inserts 26, 32 preferably are formed of the same material, e.g., an aluminum alloy. However, the inserts alternatively could be formed of a mix of composite materials, non-metals, or other metal alloys, to achieve a desired performance or cosmetic quality. Another preferred material for the inserts is PEBAX® 6333, a polyether block amide. In addition, other materials, including thermoplastics, having a low density and a hardness desired by a golfer can be utilized. Using the PEBAX® material for the inserts allows about 45 grams of the total 340 grams of the putter head 10 to be redistributed to the toe and heel regions 14, 18.

[0031] A precise thickness for the front and rear inserts 26, 32 can be provided by using a coining process. Other techniques, including machining, casting, stamping, and combinations thereof, known to those skilled in the art, alternatively could be used. The thickness of the front insert preferably is between about 0.2 mm and 4 mm, and more preferably is about 3 mm. The thickness of the rear insert preferably is between about 0.1 mm and 3 mm, and more preferably is about 2 mm.

[0032] The adhesive layers 42 for adhering the front and rear inserts 26, 32 within the respective front and rear recesses 20, 22 can be provided using adhesive tape. Such tape can have a thickness of about 0.05 mm, and it can be used as a single layer or as multiple layers, providing a total thickness of about 0.4 mm.

[0033] A part of the coining, machining, casting or stamping process may optionally include providing decorative markings on one or both of the inserts 26, 32. Mill marks, logos or other patterns may be formed. A decorative badge 46 covering all, or only a portion, of the rear insert's exposed rear surface 36 may be included, as is shown in FIG. 2. A preferred thickness for the badge is between about 0.3 mm and 0.6 mm. The material of any such badge preferably is selected such that the rear insert and badge have a combined mass within the desired range. In one embodiment, the badge is formed of a nickel alloy.

[0034] With reference now to FIG. 4, it will be observed that the front recess 20 has a substantially uniform depth. The exposed striking surface 28 of the front insert 26 is substantially flush with a surrounding front surface 48 of the putter body 12. In the depicted embodiment, this front surface 48 is inclined slightly rearwardly, so that the central wall 24 separating the front and rear recesses 20, 22 has a thickness that is non-uniform. The rear recess 22 likewise has a substantially uniform depth. The rear insert 32 and badge 46 preferably do not completely fill the volume of the rear recess.

[0035] The inclusion of front and rear inserts 26, 32 separated by the central wall 24 in the putter body 12 provides the putter head 10 with good structural integrity. It also provides greater manufacturing ease over the construction of putters having toe and heel regions that are totally separate from each other. In addition, the use of separate inserts for the front and rear of the putter head, as contrasted with a single insert extending completely through an opening in the putter body's central region 16, allows the customization of the exposed striking surface 28 for feel and of the exposed rear surface 36 for aesthetics. That is, the front insert and its attachment within the front recess 20 can be selected according to a golfer's preference in feel and sound. The rear insert and any decorative elements on it can be selected to achieve the desired head weighting and cosmetic appeal. The thickness of the central also can be modified to achieve a desired club head moment of inertia.

[0036]FIG. 5 depicts an alternative embodiment of a putter head 100 in accordance with the present invention. This putter head includes a putter body 102 having a central wall 104 that separates a front recess 106 and a rear recess 108. A front insert 110 is located within the front recess, and a rear insert 112 is located within the rear recess. In contrast with the putter head 10 of FIGS. 1-4, the front insert 110 has a non-uniform thickness and the rear insert 112 has no accompanying badge. In addition, several grooves are provided on the front insert's rear surface 114, with a central groove 116 having a depth greater than the depths of upper and lower grooves 118. This configuration allows the stiffness to be controlled from top to bottom in such a way that impact vibrations are channeled along a path of least resistance and the feel for the golfer can be tuned. Placing a suitable soft material within these grooves can help to further dampen vibrations and to soften the sound at impact. The rear insert has a logo or decorative marking 120 engraved on its exposed rear surface 112. Such marking can include a paint fill, as desired.

[0037]FIG. 7 depicts another embodiment of a putter head 200 in accordance with the present invention. In this embodiment, a putter body 202 includes a thin central wall 204 located between a front recess 206 and a rear recess 208. A front insert 210 is located within the front recess, and a rear insert 212 is located within the rear recess. The front insert has a height H1 that is substantially the same as the height H2 of the rear insert. A lower flange 214, located behind the rear insert, is tapered so as to facilitate positioning the rear insert within the rear recess during its manufacture. The exposed rear surface 216 of the rear insert is substantially flush with the portion 218 of the putter body 202 defining the rear recess's perimeter.

[0038] The thickness of the central wall 204 between the front and rear recesses 206, 208 of the putter body 202 is substantially uniform. An adhesive layer 220 in the form of a plurality of layers of tape fills a gap between the confronting surfaces of the front insert 210 and the central wall. Alternatively, the front insert can be attached to the putter body using just a single, thicker layer of tape or using another adhesive material, e.g., a suitable resin. Further, it will be noted that the central wall is located slightly more rearward than is the corresponding wall included in the putter head embodiments of FIGS. 1-4 and 5. The lengths L1 and L2 of the front and rear inserts may or may not be the same.

[0039]FIG. 8 depicts yet another embodiment of a putter head 300 in accordance with the invention. In this embodiment, a putter body 302 includes a thin central wall 304 located between a front recess 306 and a rear recess 308. A front insert 310 is located within the front recess, and a rear insert 312 is located within the rear recess. The front recess and front insert are slightly tapered such that they are thicker at their upper ends. The central wall has a minimum thickness at its upper end that is approximately the same as the uniform thickness of the rear insert. The wall has a volume that is slightly larger than those of the embodiments of FIGS. 1-4, 5 and 7, which is compensated for by configuring the front and rear inserts to have longer lengths L1 and L2. These lengths can be approximately the same.

[0040] The invention also resides in a method for manufacturing a putter head to provide desired “feel” and “sound” characteristics. The method includes the steps of:

[0041] (a) providing a plurality of putter bodies, each body having a toe region, a central region, and a heel region, the mass of each of the toe and heel regions being at least 35% of the body's total mass, the central region having a front recess and a rear recess separated by a central wall, the front recess having first uniform length and height dimensions, the rear recess having second uniform length and height dimensions, and the central wall having a thickness of at least about 0.1 mm;

[0042] (b) selecting one of the putter bodies based on desired “feel” and “sound” characteristics;

[0043] (c) providing a front insert for placement in the front recess of the selected putter body; and

[0044] (d) providing a rear insert for placement in the rear recess of the selected putter body.

[0045] In this method, the material and thickness of the front insert and the adhesive layer are selected to provide the feel desired by a particular golfer. The thickness of the central wall and its relative location—slightly rearward or central—also are selected to provide the desired putter head weighting and to address the golfer's choice of feel. Finally, the material and thickness of the rear insert and the adhesive layer are then selected, as a final step in providing the desired feel.

[0046] It should be appreciated from the foregoing description that the present invention provides an improved golf club putter head providing golfers with certain advantages, including improved performance and feel. Of course, it should be understood that not all of such advantages are necessarily achieved by every embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0047] Although the invention has been disclosed in detail with reference only to the preferred embodiments, those skilled in the art will appreciate that various modifications can be made without departing from the scope of the invention. Accordingly, the invention is defined only by the claims set forth below. 

We claim:
 1. A golf club putter head, comprising: an elongated body having a toe region, a central region, and a heel region, the central region having a front recess, a rear recess, and a central wall separating the front and rear recesses and joining the toe and heel regions; a front insert having a striking surface and a rear surface and further having a maximum thickness, the front insert being located within the front recess of the central region of the elongated body, with its striking surface exposed; and a rear insert having a rear surface and a front surface and further having a maximum thickness, the rear insert being located within the rear recess of the central region of the elongated body, with its rear surface exposed; wherein the central wall has a minimum thickness that is less than or equal to the maximum thickness of the front insert and that is less than or equal to the maximum thickness of the rear insert, and wherein the combined thicknesses of the central wall and the front and rear inserts is selected to provide enhanced putting performance for a golfer.
 2. A golf club putter head as defined in claim 1, wherein: the elongated body has a predetermined density; and the front insert comprises a metal material having a density less than the density of the elongated body.
 3. A golf club putter head as defined in claim 1, wherein the toe and heel regions of the elongated body comprise at least 70% of a total mass of the putter head.
 4. A golf club putter head as defined in claim 1, wherein at least one of the front and rear inserts has a thickness that varies along a substantially vertical direction.
 5. A golf club putter head as defined in claim 1, wherein the thickness of the central wall of the elongated body ranges between about 0.1 mm and 3 mm.
 6. A golf club putter head as defined in claim 1, wherein the thickness of both the front insert and the rear insert ranges between about 0.2 mm and 4 mm.
 7. A golf club putter head as defined in claim 1, wherein the front insert has a substantially uniform thickness.
 8. A golf club putter head as defined in claim 1, wherein the rear insert comprises a plate and an exposed decorative element.
 9. A golf club putter head as defined in claim 1, wherein the front and rear inserts comprise different materials, at least one of the materials being different from the material of the elongated body.
 10. A golf club putter head as defined in claim 1, wherein the front and rear inserts, together, have a mass that is at least 30 grams less than an equivalent volume of the material that forms the elongated body.
 11. A golf club putter head, comprising: a body formed of a metallic material having a density, the body including a toe region, a central region, and a heel region, the central region having a front recess, a rear recess, and a central wall separating the front and rear recesses and joining the toe and heel regions; a front insert having a striking surface and a rear surface, the front insert being disposed within the front recess of the central region of the body, the front insert having a maximum thickness and formed of material having a density less than the density of the body; and a rear insert having a rear surface and a front surface, the rear insert being disposed within the rear recess of the central region of the body, the rear insert having a maximum thickness and formed of a material having a density less than the density of the body; wherein the central wall has a minimum thickness that is less than or equal to the maximum thickness of the front insert and less than or equal to the maximum thickness of the rear insert.
 12. A golf club putter head as defined in claim 11, wherein the densities of the front and rear inserts are different.
 13. A golf club putter head as defined in claim 11, wherein the densities of the body, front insert, and rear insert are such that the combined masses of the front insert and rear insert are at least 10 grams less than they would be if they both had the same density as the body.
 14. A method of optimizing a golf club putter head for a particular golfer, comprising the steps of: providing a plurality of elongated club head bodies, each club head body comprising a toe region, a central region, and a heel region, wherein the combined mass of the toe and heel regions of each club head body is at least about 70% of the body's total mass, wherein the central region of each club head body includes a central wall defining a front recess and a rear recess, the front recess having first uniform length and height dimensions, the rear recess having second uniform length and height dimensions, wherein the central wall has a thickness of at least 0.1 mm; providing a plurality of front inserts for attachment in the front recess of any one of the plurality of elongated bodies, such front inserts having different uniform thicknesses, ranging between about 0.2 mm and 4 mm; providing a plurality of rear inserts for attachment in the rear recess of any one of the plurality of elongated bodies; and selecting and assembling a combination of an elongated body, a front insert, and a rear insert according to a preferred feel and sound of a putter for the particular golfer.
 15. A method as defined in claim 14, and further comprising forming the plurality of front inserts from a group of metallic and non-metallic materials.
 16. A method as defined in claim 14, and further comprising providing a plurality of adhesive tape thicknesses for attaching the selected front insert in the front recess of the selected elongated body.
 17. A method as defined in claim 14, and further comprising forming at least one of the plurality of front inserts by coining.
 18. A method as defined in claim 14, and further comprising providing a decorative badge at a rear-facing surface of at least one of the plurality of rear inserts.
 19. A method as defined in claim 14, and further comprising forming at least one of the plurality of elongated bodies with a wall thickness that varies along a vertical axis. 